6.1.1 Describe the functions of the following processor components:
accumulator, instruction register and program counter.
Further details (or registers) are not required.
In a CPU, the accumulator stores results of ongoing calculations and it is a register in the ALU. An accumulator saves intermediate data so it does not have to be saved to RAM which is much slower since the technology is slower.
In an instruction register, instructions about to be executed are stored, rather than the slower RAM.
The program counter increments with each processor cycle and contains the number of the next instructions to carry out.
The Memory Address Register stores the memory address from which data will be fetched to the CPU.
The Decoder decodes OpCodes in the instruction register. ALU: - Arithmetic Logic unit - part of the CPU which handles calculations
6.1.2 Explain the role of the above components in the execution of single
instructions in the machine instruction cycle.
Program counter:
Increments before every CPU cycle (i.e. ON or BEFORE the Fetch)
Instruction Register:
Instructions copied from RAM and then are fetched from the instruction register.
6.1.3 Describe the function of an interrupt register.
Stores the state of the program and the program interrupts so that they can be dealt with.
6.1.4 Describe how buses link the processor, the random access memory,
the read-only memory and cache.
A collection of wires through which data is transmitted from one part of a computer to another. You can think of a bus as a highway on which data travels within a computer. When used in reference to personal computers, the term bus usually refers to internal bus. This is a bus that connects all the internal computer components to the CPU and main memory. There's also an expansion bus that enables expansion boards to access the CPU and memory. All buses consist of two parts -- an address bus and a data bus. The data bus transfers actual data whereas the address bus transfers information about where the data should go. The size of a bus, known as its width, is important because it determines how much data can be transmitted at one time. For example, a 16-bit bus can transmit 16 bits of data, whereas a 32-bit bus can transmit 32 bits of data. Every bus has a clock speed measured in MHz. A fast bus allows data to be transferred faster, which makes applications run faster. On PCs, the old ISA bus is being replaced by faster buses such as PCI Nearly all PCs made today include a local bus for data that requires especially fast transfer speeds, such as video data. The local bus is a high-speed pathway that connects directly to the processor. Several different types of buses are used on Apple Macintosh computers. Older Macs use a bus called NuBus, but newer ones use PCI.
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6.1—Processor configuration
6.1.1 Describe the functions of the following processor components:
accumulator, instruction register and program counter.
Further details (or registers) are not required.
In a CPU, the accumulator stores results of ongoing calculations and it is a register in the ALU. An accumulator saves intermediate data so it does not have to be saved to RAM which is much slower since the technology is slower.
In an instruction register, instructions about to be executed are stored, rather than the slower RAM.
The program counter increments with each processor cycle and contains the number of the next instructions to carry out.
The Memory Address Register stores the memory address from which data will be fetched to the CPU.
The Decoder decodes OpCodes in the instruction register.
ALU: - Arithmetic Logic unit - part of the CPU which handles calculations
6.1.2 Explain the role of the above components in the execution of single
instructions in the machine instruction cycle.
Program counter:
Increments before every CPU cycle (i.e. ON or BEFORE the Fetch)Instruction Register:
Instructions copied from RAM and then are fetched from the instruction register.6.1.3 Describe the function of an interrupt register.
Stores the state of the program and the program interrupts so that they can be dealt with.
6.1.4 Describe how buses link the processor, the random access memory,
the read-only memory and cache.
A collection of wires through which data is transmitted from one part of a computer to another. You can think of a bus as a highway on which data travels within a computer. When used in reference to personal computers, the term bus usually refers to internal bus. This is a bus that connects all the internal computer components to the CPU and main memory. There's also an expansion bus that enables expansion boards to access the CPU and memory. All buses consist of two parts -- an address bus and a data bus. The data bus transfers actual data whereas the address bus transfers information about where the data should go. The size of a bus, known as its width, is important because it determines how much data can be transmitted at one time. For example, a 16-bit bus can transmit 16 bits of data, whereas a 32-bit bus can transmit 32 bits of data. Every bus has a clock speed measured in MHz. A fast bus allows data to be transferred faster, which makes applications run faster. On PCs, the old ISA bus is being replaced by faster buses such as PCI Nearly all PCs made today include a local bus for data that requires especially fast transfer speeds, such as video data. The local bus is a high-speed pathway that connects directly to the processor. Several different types of buses are used on Apple Macintosh computers. Older Macs use a bus called NuBus, but newer ones use PCI.
Best content in StJulians_ComputerScience | Diigo - Groups